is largely driven by water availability and is restricted to wet loca-tions that receive water during the summer snowmelt. Topographicfactors, such as micro-topography (e.g. boulders and rocks), waterdrainage, upstream catchment, slope, and intensity of solar irra-diance, all play a key role in vegetation community health anddistribution. Within the moss turves, cryo-perturbation producesridges and valleys on a centimetre scale, causing plants growingon the tops of ridges to be subject to more drying and wind abra-sion than those protected in the valleys (Fig. 2(b), Lovelock andRobinson, 2002). This contributes to the turf colour variation, withvalleys typically varying shades of green, and ridges ranging fromred through brown to black as moss becomes increasingly mori-bund.